It takes about 20 seconds for a red blood cell to circle the whole body.
102
Yawns are more contagious among people with closer relationships.
163
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Enamel is hardest substance in the human body.
61
Every year your body replaces 98% of your atoms.
119
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515